Arbuscular mycorrhizae

Definition

Arbuscular mycorrhizae are a type of symbiotic association between fungi and the roots of most land plants, where the fungal hyphae penetrate the root cells and form structures known as arbuscules. This relationship enhances nutrient uptake, particularly phosphorus, for plants and helps fungi access carbohydrates produced by photosynthesis, highlighting its critical role in plant nutrition and ecology.

5 Must Know Facts For Your Next Test

1. Arbuscular mycorrhizae are found in about 80% of terrestrial plant species, indicating their widespread importance in ecosystems.
2. These fungi are part of the Glomeromycota phylum and are crucial for improving soil structure and fertility.
3. In addition to phosphorus, arbuscular mycorrhizae can enhance the uptake of other nutrients like nitrogen and micronutrients.
4. The symbiotic relationship allows plants to thrive in nutrient-poor soils by extending their root networks through the fungal hyphae.
5. Arbuscular mycorrhizal fungi can also provide plants with increased resistance to pathogens and environmental stresses, such as drought.

Review Questions

• How do arbuscular mycorrhizae benefit plant nutrition and overall health?
  • Arbuscular mycorrhizae benefit plants primarily by enhancing nutrient uptake, especially phosphorus, which is vital for plant growth. The fungal hyphae extend into the soil beyond the root system, accessing nutrients that are otherwise unavailable to the plant. This symbiotic relationship not only boosts nutrient absorption but also helps improve soil structure, making it easier for plants to establish deeper roots and absorb water.
• Compare and contrast arbuscular mycorrhizae with ectomycorrhizae in terms of their structures and functions.
  • Arbuscular mycorrhizae differ from ectomycorrhizae primarily in their structural interactions with plant roots. While arbuscular mycorrhizae penetrate root cells to form arbuscules, ectomycorrhizae wrap around root surfaces without invading them. Both types enhance nutrient uptake for plants but are associated with different plant groups; arbuscular types are more common in herbaceous plants, while ectomycorrhizae mainly associate with trees.
• Evaluate the ecological significance of arbuscular mycorrhizae in natural ecosystems and agricultural practices.
  • The ecological significance of arbuscular mycorrhizae is profound, as they play a crucial role in nutrient cycling and plant community dynamics in natural ecosystems. Their ability to improve nutrient uptake helps sustain plant health and biodiversity. In agricultural practices, enhancing arbuscular mycorrhizal associations can lead to reduced reliance on chemical fertilizers, promote soil health, increase crop yields, and enhance resilience against pests and diseases, showcasing their importance for sustainable farming.

Related terms

Ectomycorrhizae:

A different type of mycorrhizal association where fungi form a sheath around the roots and do not penetrate the root cells, primarily associated with trees.

Fungal Hyphae: The thread-like structures that make up the body of a fungus, which spread out in the soil to absorb nutrients and form mycorrhizal associations.

Symbiosis:

A close and often long-term interaction between two different biological species, which can be beneficial, neutral, or harmful to one or both parties.